WIP résumé

1-introduction/introduction.tex

@@ -5,7 +5,8 @@
 
 %This PhD manuscript shows how wearable haptics, worn on the outside of the hand, can improve direct hand interaction in immersive \AR by augmenting the perception of the virtual content and its manipulation.
 In this manuscript thesis, we show how immersive \AR, which integrates visual virtual content into the real world perception, and wearable haptics, which provides tactile sensations on the skin, can improve the free and direct interaction of virtual objects with the hand.
-Our goal is to enable users to perceive and interact with wearable visuo-haptic augmentations in a more realistic and effective way, as if they were real. %interaction of the hand with the virtual content.%, moving towards a seamless integration of the virtual into the real world.
+Our goal is to enable users to perceive and interact with wearable visuo-haptic augmentations in a more realistic and effective way, as if they were real.
+%interaction of the hand with the virtual content.%, moving towards a seamless integration of the virtual into the real world.
 %We are particularly interested in enabling direct contact of virtual and augmented objects with the bare hand.
 %The aim of this thesis is to understand how immersive visual and wearable haptic augmentations complement each other in the context of direct hand perception and manipulation with virtual and augmented objects.
 
@@ -107,7 +108,7 @@ One of the most important aspects of this illusion is the \emph{plausibility}, \
 However, when an \AR/\VR system lacks haptic feedback, it may create a deceptive and incomplete user experience when the hand reaches the virtual content.
 All (visual) virtual objects are inherently intangible and cannot physically constrain a user's hand, making it difficult to perceive their properties and interact with them with confidence and efficiency.
 It is also necessary to provide a haptic feedback that is coherent with the virtual objects and ensures the best possible user experience, as we argue in the next section.
-The \textbf{integration of wearable haptics with \AR appears to be one of the most promising solutions}, but it remains challenging due to their respective limitations and the additional constraints of combining them, as we will overview in the next section.
+The \textbf{integration of wearable haptics with immersive \AR appears to be one of the most promising solutions}, but it remains challenging due to their respective limitations and the additional constraints of combining them, as we will overview in the next section.
 
 \begin{subfigs}{visuo-haptic-environments}{Visuo-haptic environments with varying degrees of reality-virtuality. }[][
   \item \AR environment with a real haptic object used as a proxy to manipulate a virtual object \cite{kahl2023using}.
@@ -159,9 +160,9 @@ Although closely related, \AR and \VR have key differences in their respective r
 
 %As such, in \VR, visual sensations are particularly dominant in perception, and conflicts with haptic sensations are also specifically created to influence the user's perception, for example to create pseudo-haptic \cite{ujitoko2021survey} or haptic retargeting \cite{azmandian2016haptic} effects.
 
-Many wearable haptic devices take the form of controllers, gloves or exoskeletons, all of which cover the fingertips and are therefore not suitable for \AR.
+Many hand-held or wearable haptic devices take the form of controllers, gloves or exoskeletons, all of which cover the fingertips and are therefore not suitable for \AR.
 The \textbf{user's hand must be free to touch and interact with the \RE while wearing a wearable haptic device}.
-Instead, it is possible to place the haptic actuator close to the point of contact with the \RE, \eg providing haptic feedback on the nail \cite{ando2007fingernailmounted,teng2021touch}, another phalanx \cite{asano2015vibrotactile,detinguy2018enhancing,salazar2020altering} or the wrist \cite{pezent2022design,sarac2022perceived} for rendering fingertip contact with virtual content.
+Instead, it is possible to place the haptic actuator close to the point of contact with the \RE, \eg providing haptic feedback on the nail \cite{ando2007fingernailmounted,teng2021touch}, another phalanx \cite{asano2015vibrotactile,detinguy2018enhancing,salazar2020altering} or the wrist \cite{pezent2019tasbi,sarac2022perceived} for rendering fingertip contact with virtual content.
 Therefore, when touching a virtual or augmented object, \textbf{the real and virtual visual sensations are perceived as co-localized, but the virtual haptic feedback is not}.
 It remains to be investigated how such potential discrepancies affect the overall perception to design visuo-haptic augmentations adapted to \AR.
 
@@ -180,8 +181,9 @@ We can then expect a seamless and direct manipulation of the virtual content wit
 %Since the hand is not occupied or covered with a haptic device so as to not impair interaction with the \RE, as described in the previous section, one can expect a seamless and direct manipulation of the hand with the virtual content as if it were real.
 When touching a visually augmenting a real object, the user's hand is physically constrained by the object, allowing for easy and natural interaction.
 However, \textbf{manipulating a purely virtual object with the bare hand can be challenging}, especially without good haptic feedback \cite{maisto2017evaluation,meli2018combining}. %, and one will rely on visual and haptic feedback to guide the interaction.
+In addition, wearable haptic devices are limited to cutaneous feedback, and cannot provide forces to constrain the hand contact with the virtual object \cite{pacchierotti2017wearable}.
 
-In addition, current \AR systems have visual rendering limitations that also affect interaction with virtual objects. %, due to depth underestimation, a lack of mutual occlusions,  and hand tracking latency.
+Current \AR systems have visual rendering limitations that also affect interaction with virtual objects. %, due to depth underestimation, a lack of mutual occlusions,  and hand tracking latency.
 \AR is the display of superimposed images of the virtual world, synchronized with the user's current view of the real world.
 However, the depth perception of virtual objects is often underestimated \cite{peillard2019studying,adams2022depth}.
 There is also often \textbf{a lack of mutual occlusions between the hand and a virtual object}, that is the hand can hide the object or be hidden by the object \cite{macedo2023occlusion}.
@@ -189,8 +191,8 @@ Finally, as illustrated in our interaction loop \figref{interaction-loop}, inter
 Therefore, there is inevitably a latency between the movements of the real hand and the feedback movements of the virtual object, and a spatial shift between the real hand and the virtual hand, whose movements are constrained to the virtual object touched \cite{prachyabrued2014visual}.
 These three rendering limitations make it \textbf{difficult to perceive the position of the fingers relative to the object} before touching or grasping it, but also to estimate the force required to grasp the virtual object and move it to a desired location.
 
-Hence, it is necessary to provide visual and haptic feedback that allows the user to efficiently contact, grasp and manipulate a virtual object with the hand.
-Yet, it is unclear which type of visual and haptic feedback, or their combination, is best suited to guide the manipulation of a virtual object. %, and whether one or the other of a combination of the two is most beneficial for users.
+Hence, it is necessary to provide feedback that allows the user to efficiently contact, grasp and manipulate a virtual object with the hand.
+Yet, it is unclear which type of visual and wearable haptic feedback, or their combination, is best suited to guide the manipulation of a virtual object. %, and whether one or the other of a combination of the two is most beneficial for users.
 
 \section{Approach and Contributions}
 \label{contributions}
@@ -205,7 +207,7 @@ Our approach is to:
 
 We consider two main axes of research, each addressing one of the research challenges identified above:
 \begin{enumerate*}[label=(\Roman*)]
-\item \textbf{augmenting the texture perception of real surfaces}, and % with visuo-haptic texture augmentations, and
+\item \textbf{augmenting the visuo-haptic texture perception of real surfaces}, and % with visuo-haptic texture augmentations, and
 \item \textbf{improving the manipulation of virtual objects}.% with visuo-haptic augmentations of the hand-object interaction.
 \end{enumerate*}
 Our contributions are summarized in \figref{contributions}.